uses crt;
var n, a, b, c, d, e : longint;
begin
clrscr;
write('Nhap so : '); readln(n);
if (n >= 11111) and (n <= 99999) then
begin
a := n div 10000;
b := (n - a * 10000) div 1000;
c := (n - a * 10000 - b * 1000) div 100;
d := (n - a * 10000 - b * 1000 - c * 100) div 10;
e := n - a * 10000 - b * 1000 - c * 100 - d * 10;
if (a = b) and (b = c) and (c = d) and (d = e) then
write(n,' la so ngu linh') else write(n,' khong la ngu linh');
end else write(n,' khong la so ngu linh');
readln
end.